Question re singularity

PhilipF

I read that the singularity at the centre of a black hole is always in the future since time slows down to zero the nearer you aproach it . So when a black hole evaporates ,at the moment when its mass falls below where gravity overcomes the exclusion principle does the matter in the singularity travel back into our time-frame from the future ?

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pmb_phy

PhilipF said:
I read that the singularity at the centre of a black hole is always in the future since time slows down to zero the nearer you aproach it . So when a black hole evaporates ,at the moment when its mass falls below where gravity overcomes the exclusion principle does the matter in the singularity travel back into our time-frame from the future ?
Let us not forget that all black holes are also absorbing energy too. What you have to figure out from there is whether the black hole has an net increase or net decrease in mass.

Pete

PhilipF

hello Pete
I was thinking about the situation where the Black hole has used up all the matter within reach of its gravitational field and from then on seems to have a future of losing mass due to quantum fluctuations (Hawking radiation) I did a search for the answer to this but only found the following

http://cosmology.berkeley.edu/Education/BHfaq.html#q8

", the black hole gradually shrinks. It turns out that the rate of radiation increases as the mass decreases, so the black hole continues to radiate more and more intensely and to shrink more and more rapidly until it presumably vanishes entirely.....
nobody is really sure what happens at the last stages of black hole evaporation: some researchers think that a tiny, stable remnant is left behind."

Hawking himself says "what happens when the mass of the black hole becomes extremely small is not quite clear but the most reasonable guess would be that it would dissapear completely in a tremendous final burst of emission"

mathman

I read that the singularity at the centre of a black hole is always in the future since time slows down to zero the nearer you aproach it .
What it is like inside a black hole is an open question - quantum theory and general relativity are in conflict in this regime.

The appearance of time slowing down is in the frame of an outside observer watching things fall in. These things never get there, as seen by the outside observer.

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